• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.611-615
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• 2008

Novel groups of uncultivable anaerobic thermophiles were isolated from compost by enrichment cultivation in medium with a cell-free extract of Geobacillus toebii. The cell-free extract of G. toebii provided the medium with growth-supporting factors (GSF) needed to cultivate the previously uncultured microorganisms. Twenty-nine GSF-requiring candidates were successfully cultivated, and 16 isolated novel bacterial strains were classified into three different groups of uncultivable bacteria. The similarity among these 16 isolates and a phylogenetic analysis using 16S rRNA gene sequences revealed that these GSF-requiring strains represented novel groups within the family Clostridiaceae.